Composite system



W. W. THOMPSON A COMPOSITE SYSTEM Ffiled July 28, 1921 MW skmmmmm Patented Jan. 13, 1925.

WILLIAM W. THOMPSON, OF CHICAGO, ILLINOIS.

COMPOSITE SYSTEIXI.

Application filed; July 23,

To all whom it may concern:

Be it known that I, WILLIAM W. T110111 SON, acitizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Composite Systems, of which the following is a full, clear, eoncise, and exact description, reference being had. to the accompanying drawings forming a part of this specification.

My invention relates to composite systems and more particularly to that character of composite systems in which telephone and telegraph instruments may be operated simultaneously over a single circuit.

My invention concerns itself particularly with the construction of improved means for facilitating the transmission of speech and telegraphic impulses without interference over such a circuit.

One feature of my invention contemplates the provision of a combined resistance and impedance element having four branches which device I will call herein a quadrilateral coil.

I will explain my invention more in detail by referring totlie accompanying drawing, in which Fig. 1 sets forth tcm constructed in vention; and

Fig. 2 is a cross sectional, view of my improved quadrilateral coil.

Referring more particularly to Fig. 1, I show a line circuit 10 as uniting the sta tions A, B, and C. The stations A and C are terminal stations and the station B is indicative of any one of a plurality of intermediate stations which may be utilized. At the stations A and C I show telegraph keys 11 which are adapted to send telegraphic impulses over the line circuit. The remaining. telegraph apparatus including the receiving relays and. Sounders are not shown as it is thought that the illustration of the telegraph key is suliiciently illustrative for the purposes intended.

A battery 12 is provided for use in connection with the sending of the telegraphic impulses. Condensers 1312 are included in the circuit as shown to smooth out the peaks of the telegraphic impulses. The customary short circuiting switches 14: are also shown.

The stations A, B, and C are each provided with telegraphones 15, by which I diagrammatically a sysaccordance with my in- 1s21. serial no. 488394;.

mean telephones capable of operating over a telegraphic circuit. The telegraphones are shown as complete instruments in stations B and C, their wiring being more clearly shown in connection with station A.

It is one of the prime objects of my invention to so arrange the apparatus. in connection with the telegraphonesthat the telegraphic impulses will not demagnetize the permanent magnets employed in connection with the telegraphones.

As indicative of the arrangement and wiring of the telegraphones, I will describe the arrangement diagrammatically shown in 7 connection with station A.

A conductor 16 leads to one terminal 17 of the telegraphone and a conductor 18 leads to the other terminal 19 of the telegraphone, the conductor 16 being connected to the line wire 10 and the conductor 18 being grounded as shown, the circuit herein illustrated being a grounded circuit.

The telegraphones are each provided with receivers 20 and transmitters 2 1. Each of the telegraphones is also provided with a howler 22 which is inserted in a suitable compartment having a perforated cover 23.

The telegraphones are also provided with an induction cell 2 1 which may actuate a vibratory element 25 having a back contact 26 for the purpose of sending signals over the line circuit to call the other stations. A condenser 27 is connected across the elements 25 and 26 for purposes well understood in the art.

A battery 28 is provided which serves for talking purposes and the transmission of calling signals.

The telegraphone also includes a switch hook 29 having the back contact 30 and the front contacts 31 and 32. The induction coil 24L has the primary winding 33 and the secondary winding 84.

A. switch is also provided operable by a finger piece 35 which serves to transmit calling signals over the circuit whenever any one station desires to call another. This switching device includes the contact lever or spring 36 which is associated witl a front contact spring 3'? and two back contact springs 38 and respectively. The howler 22 is of the customary form having a permanent magnet 4.0 with an operating coil 41-1 and a diaphragm -12 actuated thereby. This howler is associated with a quadrilateral coil consisting of two impeda-nces 43 and 44 and two non-inductive resistances 45 and 46. The receiver 20 is also associated with a quadrilateral coil having the two impedances 47 and 48 and two non-inductive resistances 49 and 50.

The term quadrilateral coil may not be the best descriptive term that can be used for this coil but I am using it herein as it is an easily understood expression for the particular device here under discussion. This quadrilateral coil, as apparent, has four branches connected together to form a continuous conductor, the points of meeting of the various branches serving as terminals through which the coil is included in circuit. The various parts are wired up as shown, the incoming talking circuit, for instance, extending by way of conductor 16, conductor 51, secondary winding 34 of the induction coil, conductor 52, non-inductive resistance 49, conductor 53, telephone receiver 20, conductor 54, non-inductive resistance 50, conductor 55 through the front contact 32 of the switch hook which is then in its raised position, conductor 56, contact springs 37 and 36, conductor 57 and conductor 18 to the ground. The transmitter is, during this order of things, connected in a local circuit with the battery 28 and the primary winding 33.

In order to transmit a calling signal from the station A, the spring 36 is pushed into its alternative position, thus closing the circuit which extends from battery 28 by way of conductor 58, primary winding 83, contact spring 25, back contact 26, contact springs 39 and 36 by way of conductors 57 and 59 to the battery 28. This causes an actuation of the vibratory element 25 and the impulses induced thereby in the secondary winding 34 are transmitted over the line of circuit by '7 way of conductor 18, conductor 57, contact springs 36 and 38, conductor 60, secondary winding 34, and conductors 51 and 16 to the line wire 10.

It will be noted that the talking circuit,

for instance, passes through the telegraphone Y without having to pass through the impedances 47 and 48. The branches of this quad rilateral coil are so arranged from a resistance standpoint that a Wheatstone Bridge proportion is maintained, for instance in this manner: that the resistance of the coil 47 is to the resistance of the coil49 as the resistance of the coil 50 is to the resistance of the coil 48.

In the particular form used herein, the

The telephonic currents being given regard to the inductive effect to the coils. The telegraphic impulses which may leak through the conductor 16 and through the quadrilateral coil consisting of the branches 42, 43, 44 and 45 will not demagnetize the nals 67 and 68 are of the same potential 7 whenever telegraphic impulses are transmitted over the .line so that the telegraphone 15 which is connected at theseterm nals 67 and 68 receives no leakage current V r from the telegraphic impulses but is entirely immune to any injurious influence from the transmission 0t telegraphic 1mpulses.

It will be noted that at station B the telegraphone 15 is connected in the circuit without being connected to the ground, the conductor 16 being connected to the terminal 67 and the. conductor 18 being connected to the terminal 68.

The telegraphones are thus adapted for serial 1nclus1on 1n the line and bridged 1nclusion to the line.

This is due to the fact that the instrumentalities through WhlGll conversation may have to be carried on in case the instrument is connected serially in the line are not of a high enough impedance to prevent successful speech transmission therethrough, such coils .in one of the embodiments of my invention being wound to about fifty ohms. The impedance, 5

however, is highv enough so thatwhen the instrumentsare bridged to the line, there is not suflicient leakage to.impair the telephonic speech transmission beyond what A is necessary for satisfactory conversation.

It will be understood, of course, that the devices do not contemplate that an unlimited number of telegraphones may be included in this connection as the service: for

which the device is, particularly used generally does not require more than five or six of such instruments upon a given line circuit. a i

rThersignalling and voice currents emanating from the telegraphone 15 ,at station B pass over conductor 10, non-inductive resistance 65, conductor 18, telegraphone 15, conductor 16, non-inductive resistance 66 to the line wire 10.-

In Fig. 2 I show the manner. in which my improved quadrilateral coil is wound.

I take a core 69 Which is of suitable mag netic material and provide it with suitable insulating heads 70. I then wind one of the inductive branches such, for instance, asthc branch 33, directly upon the core and wind the second inductive branch 6% over the lirst branch. 1 find that it is well to have both branches 63 and 64c given the same number of turns. This will make the resistances unequal but that is contemplated as has alreat v been described. The two non-inductive branches $5 and 66 are then wound about the branch 64 as shown. Each non-inductive branch is wound non-inductively by having the wire torming the branch double back on itself.

It is, of course, of extreme importance that the inductive and resistance effects be in harmony with the plan outlined herein so that there will be no difference potential, for instance, at the terminals 6'? and 68 whenever direct or telegraphic currents pass over the line Wire 10.

For this reason I find it of great importance to have the two inductive branches and 64- wound upon the same core 69. It is not of such great importance to have the non-inductive branches wound upon the same core but by placing them upon the same core, a self-contained unitary element is provided having but four terminals which can be easily marked so that it can be easily installed in a line circuit by linemen and others not familiar with the intricacies of Wiring such things as coils and similar elements.

I have found, for 1nstance, that l obity of the arrangement makes it practical.

From Whathas been thus described it is thought that the nature of my invention will be readily clear to those skilled in the art. Having, however, thus described various forms which my invention make take, what I claim as new and desire to secure by Letters Patent is:

l. A combined telephone and telegraph system comprising a line circuit, telegraph instruments connected thereto for the transmission oi telegraphic impulses thereover, a plurality of telephone instruments adapted for operative connection with said line circuit, each of said telephone instruments comprising a quadrilateral resistance and reactance coil across which the telephone receiver is bridged, asimilar coil having a translating device comprising a permanent magnet bridged there-across, both connected with the line circuit, and switching means whereby one cit said quadrilateral coils is cut out o't circuit when said other quadrilateral is thrown into said circuit.

2. A combined telephone and telegraph system comprising a line circuit, telegraph instruments connected thereto for the transmission of telegraphic impulses thereover, a plurality of telephone instruments adapted for operative connection with said line circuit, each of said telephone instruments comprising a qrlrilateral resistance and reactance coil connected with the line circuit across which the telephone receiver is bridged, and a similar coil connected with the line circuit having a howler bridged thereacross.

In witness whereof, I hereunto subscribe my name this 19th day oi? July D, 1921.

WILLIAM l/V. THOMPSON. 

